The new diploid grapevine variety of the present invention was created during the course of a grapevine breeding program that was carried out in Australia wherein two parents were crossed which previously had been studied in the hope that they would contribute the desired characteristics. The female parent (i.e., seed parent) was the ‘Hunisa’ variety (non-patented in the United States). The male parent (i.e., pollen parent) was a complex unreleased selection created in Australia at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and designated ‘M 37-02’ (non-patented in the United States). ‘M 37-02’ was bred by crossing a selection of Vitis longii with another unreleased selection of the same entity designated ‘M 39-11’ (non-patented in the United States) which was an open-pollinated seedling of the Vitis vinifera ‘Danogue’ variety (non-patented in the United States). The parentage of the new variety of the present invention can be summarized as follows:
                    ‘        Hunisa        ’                                                                                                                ‘        Danogue        ’                                                                                        Vitis        ⁢                                  ⁢        vinifera                    ×                      [                  Vitis          ⁢                                          ⁢          longii                            ×                      (                  Vitis          ⁢                                          ⁢          vinifera                            ×                                                          Vitis              ⁢                                                          ⁢                              spp                .                                      )                    ]                .            
The controlled cross that resulted in the production of the new variety of the present invention was carried out during Spring 1992 (Southern Hemisphere). Since the female parent was pollen infertile, its inflorescences were placed in pollen-proof bags before the flowers opened. The bags were removed at the appropriate time and pollen from the male parent was applied to the receptive stigma of the female parent. Such pollen had been collected from unopened flowers of male parent, and thereafter was dried in Petri dishes at 40° C. under conditions where contamination by other Vitis pollen was precluded. The resulting seeds from the cross were extracted from the fruits in Autumn 1993 (Southern Hemisphere) and were sown in a greenhouse while employing standard seed bed conditions. Emergent seedlings were transferred to standard potting mix and were maintained in pots under greenhouse conditions until they were planted in a vineyard during Spring 1993 (Southern Hemisphere). Thereafter, the plants were grown and evaluated while using standard grapevine cultivation conditions.
A single plant of the new variety was selected during 2002 from among the resulting siblings. The new variety was found to possess a combination of characteristics unlike that of its siblings and unlike that of either of the respective parent plants. The resulting plant has been carefully observed, tested and evaluated in replicated plantings and trials while growing on its own roots or when top-worked onto a range of grape rootstocks.
It was found that the new grapevine of the present invention displays the following combination of characteristics:                (a) displays high stenospermocarpic fruit production,        (b) forms in abundance late-ripening large bunches of sweet firm crisp substantially elliptic-to-obovate berries which develop a green to yellow-golden coloration at maturity and provide the capability for long-term storage, and        (c) is particularly well suited for the production of table grapes.        
The new variety well meets the needs of the horticultural industry. It can be grown to advantage for the production of table grapes for fresh fruit consumption. It also may be used for the production of dried vine fruit, or for the making of wine. The new variety is capable of providing a late-season supply of quality grapes that well maintain their character under cool storage. Satisfactory storage qualities have been observed for up to three months and make possible the servicing of export markets as well as the domestic market. The berries possess an attractive distinctive waxy bloom that serves to enhance their visual appeal, provided care is given during handling.
The attractive berries are substantially elliptic-to-obovate in configuration with some tapering towards the pedicel end. Natural berries commonly weigh approximately 4 to 5 g, are approximately 18 mm in diameter, and are approximately 24 mm in length. Under highly managed conditions with bunch trimming and thinning, berry weights of 6 to 10 g, berry diameters of 20 to 25 mm and berry lengths of 25 to 30 mm have been observed. Berry size may be increased by the application of growth regulators including combinations of 2 to 8 ppm gibberellic acid and 1.5 to 4.5 ppm of N-(2-chloro-4-pyridinyl)-N′-phenylurea.
In order to optimize fruit quality, shoots may be removed from vines and bunches subjected to thinning and trimming. It has been found for better results that five to seven lateral shoots with bunches should be retained on each vine with the removal of all non-fruitful shoots in order to reduce the density of the plant canopy. It has been found that vines of the new variety are very fruitful even in sub-tropical environments and can be spur pruned so as to reduce production costs commonly associated with cane pruning.
It has been found that best results are achieved when harvesting is delayed until the juice sugar concentration reaches approximately 19.5° Brix or until the sugar-to-acid ratio of the juice is greater than approximately 32:1. At this stage of ripening, the skin of the berries is light green to pale cream in coloration.
The new variety of the present invention can be readily distinguished from its parental varieties and other presently available grape varieties. The ‘Hunisa’ female parent forms seeded large red berries, displays leaves and fruit that are more susceptible to downy mildew (Plasmopara vitcola), and exhibits poorer fruit set in large plantings. The ‘M 37-02’ male parent forms seeded small green berries and leaves that are more susceptible to downy mildew. When the new variety is compared to the widely grown ‘Sultana’ table grape variety, sometimes known as ‘Thompson Seedless’ (non-patented in the United States), it is found that the new variety ripens later, forms larger natural fruit in the absence of hormone application, and displays superior fruit storage characteristics.
The new variety of the present invention has been found to undergo asexual propagation in Australia, by a number of routes including budding, top-working, and the rooting of cuttings. Accordingly, the new variety has been found to undergo asexual propagation in a true-to-type manner. During such propagation, the new variety has been found to be compatible with a wide range of rootstocks.
The new variety was named ‘M 44-14’.